A method and system is provided for rendering bicubic surfaces of an
object on a computer system. Each bicubic surface is defined by sixteen
control points and bounded by four boundary curves, each corresponding to
an edge, and each boundary curve is formed by boundary box of line
segments formed between four of the control points. The method and system
of include transforming only the control points of the surface given a
view of the object, rather than points across the entire bicubic surface,
and using the four boundary edges for purposes of subdivision. Next, a
pair of orthogonal boundary curves to process is selected. After the
boundary curves have been selected, each of the curves is iteratively
subdivided and the pair of orthogonal internal curves, wherein two new
curves are generated with each subdivision. The subdivision of each of
the curves is terminated when the curves satisfy a flatness threshold
expressed in screen coordinates, whereby the number of computations
required to render the object is minimized.